JP3211443B2 - Alcohol detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alcohol detecting device used to prevent a drunker from driving a car.

[0002]

2. Description of the Related Art In recent years, traffic accidents caused by automobiles are a major social problem. Above all, accidents caused by drunk driving are highly likely to be serious accidents, and there is no tendency to decrease at all.

Conventionally, as an apparatus for preventing such a drunk driving, as described in Japanese Patent Publication No. 51-21698 and US Pat. No. 3,855,573, one end of a pipe is connected to a suction pump. The end is placed near the driver's seat in the cabin and opened, a part of the driver's breath is introduced into the pipe by a suction pump, and the alcohol in the driver's breath is actuated by the operation of the alcohol component detection element installed in the middle of the pipe. There is a device that determines the concentration and disables the vehicle.

However, according to the above-described conventional technology, when actually determining the alcohol concentration in the breath of the driver,
There were some problems.

The first problem is that the gas inhaled by the pump is mixed not only with the driver's exhalation but also with the air in the passenger compartment, so whether the inhaled gas contains the driver's exhalation or not. It is necessary to determine whether or not the above-described conventional technology is provided with such a determination unit, and there is a possibility that an erroneous determination is made.

To solve this problem, Japanese Patent Publication No. 56-18898
As described in Japanese Patent Application Laid-Open Publication No. H10-209, a technique of installing a pressure sensor in a pipe and measuring a pressure change in the pipe has been proposed.
However, such a method is effective for a deception action such as closing an intake port, but it is not accurate enough to determine whether or not a driver blows out expiration toward the intake port. Even if the pressure sensor described above is used, there is a possibility that erroneous determination of exhalation will occur if appropriate air is sent instead of exhalation.

Further, as described in Japanese Patent Publication No. 56-18898, there is disclosed a technique for judging expiration based on changes in humidity and temperature. However, deception such as holding a wet hand near an inhalation port has been disclosed. It is easily possible.

[0008] The second problem is that the state in which the expiration is blown toward the inhalation port usually depends on the driver, so the amount and direction of the expiration are not constant, and are therefore contained in the inhaled gas. This is because an error occurs in the determination of the alcohol concentration because the rate of expiration is not constant. Further, it is practically impossible for the driver to blow out the determined exhalation volume with good reproducibility.

[0009] The third problem is the speed of judging the alcohol concentration. That is, this type of device is operated immediately before the vehicle runs, and it is often uncomfortable for the driver to take a long time for this determination, and it is necessary to make the determination as quickly as possible. However,
The currently known alcohol detection element has a response time (time from when the alcohol gas contacts the element until the output signal of the element becomes a value corresponding to the alcohol concentration and stabilizes).
There is nothing that can be sufficiently satisfied.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above three problems, namely, determination of driver's expiration, correction of fluctuations in inspired expiration volume, and improvement of the determination speed. An object of the present invention is to provide an alcohol detection device suitable for preventing driving.

[0011]

According to a first aspect of the present invention, one opening (first opening) is provided toward a space to be measured, and the other opening is connected to the opening. A sulfide sensor provided in the suction unit for determining whether or not human breath is contained in the inhaled gas to be detected; and a sulfide sensor provided in the suction unit. A humidity sensor for calculating the amount of expiration contained in the gas to be detected; an alcohol sensor provided in the inhalation unit for detecting alcohol contained in the gas to be detected; and the sulfide. A breath presence / absence determiner that determines the presence or absence of breath based on a ratio between a detection signal of the sensor and a detection signal of the humidity sensor, and an alcohol determination device that determines alcohol concentration from a ratio of the detection signal of the alcohol sensor and the detection signal of the humidity sensor. It includes a call concentration determination unit, and is characterized by detecting the alcohol concentration of the detection target gas passing through the suction portion.

In the above invention, the sulfide sensor is a device for detecting a sulfide component contained in the air flowing through the suction portion, and specifically, for detecting methyl mercaptan which is a main component of human bad breath. It is assumed that. As the sulfide sensor, for example, a gas detector that uses an oxide semiconductor such as tin oxide to generate a resistance change due to a sulfide oxidation reaction is used.

The humidity sensor is a device used to detect water vapor contained in the air flowing through the inhaler, and to correct the influence of fluctuations in the inhaled breath volume. As the humidity sensor, for example, a humidity detector that changes the capacity of the polymer film due to the adsorption of water can be used.

The alcohol sensor is a device for detecting an alcohol component contained in air flowing through the suction section.
As the alcohol sensor, for example, a gas detector that uses an oxide semiconductor such as tin oxide to generate a resistance change accompanying an oxidation reaction of alcohol can be used.

Also, the breath presence / absence judging device determines a ratio (Δ sulfide / Δ humidity) of a change amount (Δ sulfide) of the detection signal of the sulfide sensor to a change amount (Δ humidity) of the detection signal of the humidity sensor. )) To determine the presence or absence of exhalation.

Further, the alcohol concentration judging device calculates the alcohol concentration based on the ratio (Δalcohol / Δhumidity) of the change amount (Δalcohol) of the detection signal of the alcohol sensor and the change amount (Δhumidity) of the detection signal of the humidity sensor. This is to determine the density.

According to a second aspect of the present invention, there is provided an alcohol detecting apparatus according to the first aspect, wherein the alcohol sensor, the sulfide sensor, and the humidity sensor have the same gas response time constant. That is, when the response time constants of the alcohol sensor, the humidity sensor, and the sulfide sensor are different, for example, a film that delays gas diffusion is attached around the sensor element to make the time constants of the three sensors equal. Further, in order to sufficiently exhibit the effect of equalizing the time constant of the response, it is preferable that the three sensors are installed close to each other so that the inhaled air contacts at the same time.

According to a third aspect of the present invention, in the above-mentioned invention, a three-way valve installed between the three sensors and a first opening installed toward a space to be measured (vehicle compartment);
One end of a tube constituting the second suction portion is connected to the three-way valve, and the other end of the tube is provided with a second opening provided near the driver's seat and at a position where it is difficult for the driver to inhale. An alcohol detection device characterized by adding a second suction unit. The three-way valve is a valve having valve means for switching between suction from a first opening and suction from a second opening. The three-way valve includes a first opening, a second opening, and the three sensors. It is installed between. The first opening is for inhaling the driver's exhalation, and is provided at a position where the exhalation of the exhaled air can be easily taken when the driver is seated in a driving posture, for example, near the steering column. is there. The second opening is for inhaling the air in the passenger compartment near the driver, and is installed near the driver's seat where it is difficult for the driver's breath to be inhaled. For example, the second opening is preferably near the ceiling above the driver's seat.

As another configuration of the present invention, in the above invention, a device for disabling the running of the vehicle by a warning by a lamp or a buzzer or by an ignition interlock or a shift lever interlock based on the alcohol concentration determination value is added. An alcohol detection device, characterized in that:

[0020]

In the present invention, the sulfide sensor is an effective means for determining the driver's expiration, which is the first problem of the above-mentioned prior art. That is, in order to determine whether or not the driver's breath is present in the air (gas to be measured) sucked into the suction part, it is preferable to use a substance or characteristic peculiar to human breath. Therefore, as a result of an investigation, it was found that methyl mercaptan is suitable as a specific substance contained in human breath. Methyl mercaptan is a kind of sulfide and is a main component of bad breath, and it has an unpleasant odor even at a low concentration. The concentration of methyl mercaptan in the mouth varies depending on the individual and the condition of the mouth, but it is known that many adults always exist at a certain concentration or more. Methyl mercaptan has only a very low concentration in ordinary air, and if present at a high concentration, it has a very unpleasant smell, so it can be said that this is a very exceptional vehicle interior environment. Therefore, by using a sulfide sensor that can measure methyl mercaptan,
It is possible to accurately determine whether or not it is exhalation,
It is difficult to perform deception.

In the present invention, the humidity sensor is an effective means for compensating for the second problem of the prior art mentioned above, which is the effect of the change in the exhaled air volume in the gas to be detected. In order to correct the influence of the change in the inhaled expiratory volume, it is better to measure the concentration of a substance proportional to the expiratory volume, but it has been found that water vapor is suitable as such a substance. The amount of water contained in human breath is almost constant, and is usually 34%.
It corresponds to a saturated vapor pressure of ° C. Therefore, as shown in FIG. 1, the alcohol concentration in the mouth and the (alcohol concentration / water vapor concentration) in the mouth are in a proportional relationship. Since this proportional relationship is considered to be the same even when the exhaled air is diluted in the air, this ratio, that is, the change amount of the detection signal of the alcohol sensor (Δ alcohol) and the change amount of the detection signal of the humidity sensor (Δ alcohol) If the ratio (Δalcohol / Δhumidity) can be measured, the alcohol concentration in the mouth can be calculated using FIG.

The slope of the correlation diagram shown in FIG. 1 corresponds to the reciprocal of the water vapor concentration in the mouth. If, for example, the saturated steam pressure at 34 ° C. (39.9 mmHg or 52,500 ppm) is adopted as the steam concentration in the mouth, the slope becomes 1
/39.9 (mmHg ^-1 ) or ^{1 /} 52,500 (p
pm ^-1 ).

As described above, by measuring the water vapor concentration using the humidity sensor and determining the alcohol concentration as a function of Δalcohol / Δhumidity of the gas to be detected, the influence of the change in the exhaled air volume in the gas to be detected is corrected. It is possible to do.
Of course, there are many things other than exhalation that cause a change in humidity.However, since only the gas determined to be exhaled by the sulfide sensor is targeted, erroneous determination due to an action such as holding a wet hand over the inlet can be avoided. .

In the present invention, making the response time constants of the alcohol sensor, the sulfide sensor, and the humidity sensor equal contributes to the improvement of the determination speed and the measurement accuracy in the determination of the alcohol concentration and the sulfide concentration. This is an effective means for the third problem of the prior art described above. Taking the determination of the alcohol concentration as an example, as shown in FIG. 2, the detection target gas including the exhaled breath is inhaled, and the determination is made at a time point A at which the alcohol sensor and the humidity sensor stabilize to a constant value corresponding to the respective gases. It is quicker to calculate the ratio of the output changes of the two sensors and make the determination at time B when the ratio becomes constant. In order to perform the density determination using such a method, it is preferable to make the response time constants of the sensors equal. The same is true for sulfide detection.

In the present invention, the two openings for inhalation are provided because the difference in the positions of the openings is used to influence the effect of alcohol-containing gas such as hair tonics and the effect of drinkers on the passenger seat. In order to subtract Since hair tonics and perfumes contain alcohol in their components, even drivers who do not drink alcohol may be erroneously detected as breath alcohol. Therefore, in the present invention, the detection signal of the air entering through the first opening and the change amount of the detection signal of the air entering through the second opening are compared, and the difference is subtracted from the amount other than exhalation such as hair tonic. It cancels the effects of alcohol.

That is, in the case where air enters through the first opening provided at a position where the expiration is easy to enter, as shown in FIG. The sensor responds and the output appears as the sum of the two (see curve a). In contrast, the second
3B, the output of the sensor appears for alcohol such as hair tonic as shown in FIG. 3B (see curve b). The reason for this is that, because the driver blows out forward, most of the expiration reaches the sensor via the first opening, so that the difference in the amount of the expiration component depending on the position of the first and second openings is large, On the other hand, in the case of a hair tonic or the like, since the gas reaches the sensor by natural diffusion, the difference in gas concentration between the first and second opening positions is small. In addition, since alcohol generated from a drinker in the passenger seat has a long distance to the opening, the difference depending on the position of the opening is small like the hair tonic. Therefore, by subtracting the detection signal amount of the alcohol sensor of the air inhaled from the second opening from the detection signal amount of the alcohol sensor of the air inhaled from the first opening, the sensor response to the true exhaled alcohol component is obtained. (ΔAc) can be obtained.

According to the detection device of the present invention, about 10-1,
000 ppm of breath alcohol can be detected. However, the concentration of breath alcohol is 1,000 ppm
In this case, the concentration usually corresponds to a deep paralysis or lethal level, which is practically negligible.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

[0029]First embodiment  FIG. 4 is a schematic diagram illustrating an arrangement relationship in the present embodiment.

The detected gas suction section 10 includes a suction pipe 12 and a suction pump 14. The suction pipe 12
One end is fixed to the pipe 140 of the steering column 120, and the other end is inserted and supported by a wall of a box-shaped mounting portion 160 provided in the engine room 100. One end of the suction pipe 12 has a trumpet-shaped opening 12a opened at a position where the breath of the driver can be efficiently collected.

The suction pump 14 is installed in a mounting portion 160, and an exhaust port 1 formed in a wall of the mounting portion 160 is provided.
The gas to be detected is exhausted via 6.

In addition, approximately in the middle of the suction pipe 12,
A sensor mounting portion 20 is configured, and an alcohol sensor 22
The humidity sensor 24 and the sulfide sensor 26 are provided in a predetermined arrangement relationship.

The alcohol sensor 22 is connected to the suction pipe 12
This is a sensor for detecting an alcohol component contained in air flowing through the inside, and for example, "TGS822" manufactured by Figaro Giken using a semiconductor of tin oxide can be used.

The humidity sensor 24 is a sensor for detecting water vapor contained in the air flowing through the suction pipe 12.
For example, a capacitive variable humidity sensor manufactured by Vaisala can be used.

The sulfide sensor 26 is a sensor for detecting a sulfide component contained in the air flowing through the suction pipe 12. In this embodiment, the sulfide sensor 26 is for detecting methyl mercaptan which is a main component of human bad breath. I have. As the sulfide sensor, for example, "TGS825" manufactured by Figaro Giken using a semiconductor of tin oxide can be used.

The alcohol sensor 22, the humidity sensor 24 and the sulfide sensor 26 are provided with a film for delaying gas diffusion around each of the three sensor elements in order to make the response time constants equal. For example, it is preferable to mount a porous cellulose membrane (film thickness 100 μm, pore diameter 0.1 μm).

Further, in order to sufficiently exhibit the effect of equalizing the response time constants of the sensors 22, 24, and 26, it is preferable that these sensors are arranged as close as possible.

FIG. 5 is a circuit diagram of the detection device of this embodiment. The detection circuit of the present embodiment includes an alcohol sensor 22, a humidity sensor 24, and a sulfide sensor 26. Detection signals of the alcohol sensor 22 and the humidity sensor 24 are output to the alcohol concentration determiner 30,
And the detection signal of the sulfide sensor 26
It is configured to be output toward 0.

The alcohol concentration determiner 30 is configured to calculate the alcohol concentration based on the input detection signal and determine the alcohol concentration. Specifically, the divider 32, the reference value setting circuit 36, It comprises a comparison circuit 34.

Based on the detection signals output from the alcohol sensor 22 and the humidity sensor 24, the divider 34 determines the alcohol concentration (Δ alcohol) and the water vapor concentration (Δ
And the calculated value is output to the comparison circuit 34.

The reference value setting circuit 36 is a circuit for providing a reference value for setting the alcohol concentration. For example, as a drunk driving level, an alcohol concentration of 120 ppm
Is set, a voltage signal corresponding to the value is output.

The comparison circuit 34 includes a reference value setting circuit 36
And the signal of the divider is given to the display device 50 as a signal. For example, if the voltage signal of divider 32 is larger than the voltage signal of reference value setting circuit 36, comparison circuit 34 outputs an L level voltage signal, and vice versa, outputs an H level voltage signal.

The exhalation presence / absence determination unit 40 is configured to calculate the sulfide (methyl mercaptan) concentration based on the input detection signal and determine the presence or absence of exhalation. Value setting circuit 46 and comparison circuit 4
4

The divider 42 calculates the ratio between the sulfide concentration (Δ sulfide) and the water vapor (Δ humidity) based on the detection signals output from the humidity sensor 24 and the sulfide sensor 26, and calculates the calculated value. Is output to the comparison circuit 44.

The reference value setting circuit 46 is a circuit for providing a reference value for judging the presence or absence of exhalation. For example,
The reference value setting circuit 46 is configured to output a voltage signal corresponding to the value when the concentration of methyl mercaptan is set to 0.1 ppm as the level of the presence or absence of exhalation.

The comparison circuit 44, like the comparison circuit 34, is configured to give the magnitude relationship between the signal of the reference value setting circuit 46 and the signal of the divider 42 to the display device 50 as a signal. For example, if the voltage signal of divider 42 is smaller than the voltage signal of reference value setting circuit 46, comparison circuit 44 outputs an L level voltage signal, and vice versa.
Outputs a level voltage signal.

The display device 50 indicates to the driver the operation status of the alcohol detection device and the alcohol concentration determination result from the signals given by the alcohol concentration determiner 30 and the breath presence / absence determiner 40.

For example, when the voltage signal of the exhalation presence / absence determining unit 40 is at the L level, it indicates that the measurement is in a waiting state for the exhalation of breath, and when the voltage signal is at the H level, it indicates that the measurement is in progress. .

The voltage signal of the expiration determination unit 40 is H
In the case of the level, when the voltage signal of the alcohol concentration determiner 30 is at the L level, it indicates that the level is the drunk driving level, and when the voltage signal is at the H level, it indicates that the level is the normal level.

Second Embodiment FIG. 6 is a schematic diagram showing a second embodiment of the present invention. Members having substantially the same configuration and function as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The second embodiment differs from the first embodiment in that a second opening 60a is provided at a position different from the opening (first opening) 12a. The second opening 60a is connected to the gas to be detected 10 through the suction pipe 60.
Is connected to the suction pipe 12 of the first stage. The second opening 60
a is installed in the vicinity of the driver and at a position where the expiration is difficult to be inhaled. In the case of this example, the second opening 60a is
The suction pipe 60 is provided in a roof header portion located slightly forward of the driver, and the suction pipe 60 passes from inside the ceiling lining of the roof header section to the inside of the right front pillar, passes through the inside below the instrument panel, and attaches a sensor to the suction pipe 12. Part 20
And the first opening 12a are connected via a three-way valve 62.

FIG. 7 is a circuit diagram of the detection device according to the second embodiment.

In this detection circuit, the three-way valve 62
A timer relay 64 for controlling the switching between the two, and a memory circuit 66 for storing a detection signal from the alcohol sensor 22.
And a subtractor 68 to which a signal from the memory circuit 66 is input.

The three-way valve 62 is controlled to be switched at a predetermined time by a signal output from the timer relay 64, and the first opening 12a or the second opening 60a is controlled.
, The gas to be detected is selectively sucked into the suction pipe 12. The detection signal S1 of the alcohol sensor 22 for the gas to be detected sucked from the first opening 12a and the detection signal S2 of the alcohol sensor 22 for the gas to be detected sucked from the second opening 60a are determined by a timer. The signals from the relay 64 are stored separately in synchronization with the opening and closing of the three-way valve 60, and these detection signals are output to the subtractor 68. In the subtractor 68, the difference between the detection signal S1 and the detection signal S2 output from the alcohol sensor 22 is obtained, and the calculated value is output to the alcohol concentration determiner 30. The structures and functions of the alcohol concentration determiner 30, the exhalation presence / absence determiner 40, and the display device 50 are the same as those in the first embodiment, and a detailed description thereof will be omitted.

According to this embodiment, from the alcohol content in the gas to be detected inhaled through the first opening 12a, the alcohol content other than the exhaled breath inhaled through the second opening 60a,
For example, by subtracting the alcohol contained in cosmetics and medicines such as hair tonics and perfumes and the alcohol contained in the breath of passengers other than the driver, the alcohol contained in the breath of the driver can be detected with higher accuracy. it can.

Further, in the present invention, it is possible to add a device for disabling the running of the vehicle by means such as a warning by a lamp or a buzzer, an ignition interlock or a shift lever interlock, based on the alcohol concentration determination value. desirable.

FIG. 8 shows an example of a control circuit for the ignition interlock. In this control circuit, signals from the alcohol concentration determiner 30 and the breath presence / absence determiner 40 are output to an AND circuit 70,
The signal from 0 is output to the relay 72. The relay 72 is connected to a normally open OK switch 74 for driving an ignition circuit 78, and the ON / OFF control of the OK switch 74 is performed by the operation of the relay 72. FIG.
In the figure, 76 indicates a main switch, and 80 indicates a battery.

In such a circuit, the driver cannot operate the ignition circuit 78 simply by turning on the main switch 76. That is, when both the output signals from the alcohol concentration determiner 30 and the breath presence / absence determiner 40 are at the H-level voltage (when the alcohol concentration is equal to or less than the predetermined value and it is determined that there is breath).
Only when the OK switch 74 is turned ON by the relay 72,
The operation of the ignition circuit 78 is enabled, and the vehicle can be started.

In the control circuit for the shift lever interlock, for example, as shown in FIG. 9, a relay 72 is connected to a normally closed electromagnetic lock switch 82 for driving a shift lever electromagnetic lock circuit 84. In this circuit, the driver can start the engine by a switch (not shown), but the shift lever is an electromagnetic lock switch 8.
2 and is inoperable. The alcohol concentration determiner 30 and the breath presence / absence determiner 4
Only when both the output signals of 0 are at H level, the electromagnetic lock switch 82 is opened by the relay 72, the operation of the shift lever electromagnetic lock circuit 84 is stopped, and the shift lever becomes operable.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these, and various modifications can be made within the scope of the invention.

The present invention can be applied not only to vehicles but also to portable alcohol detection devices suitable for self-management of drinking, for example.

[0062]

According to the present invention, the driver's expiration determination, correction for fluctuations in the inhaled expiration volume, and improvement in the determination speed are performed, and the breath alcohol in the gas to be measured is detected with high accuracy. Thus, it is possible to provide an alcohol detection device suitable for preventing automobile driving.

[Brief description of the drawings]

FIG. 1 is a diagram showing the correlation between the alcohol concentration in the mouth and the alcohol concentration / water vapor concentration in the mouth.

2 shows a response curve of a sensor, FIG. 2 (a) shows a response curve of an alcohol sensor, FIG. 2 (b) shows a response curve of a humidity sensor, and FIG. 2 (c) shows a response curve of an alcohol sensor. 5 is a curve showing (change) / (change in response of humidity sensor).

FIG. 3 shows a response curve of an alcohol sensor, and FIG.
3A shows a response curve of the gas to be detected sucked from the first opening, and FIG. 3B shows a response curve of the gas to be detected sucked from the second opening.

FIG. 4 is a schematic diagram showing a first embodiment of the present invention.

5 is a circuit diagram of the detection device shown in FIG.

FIG. 6 is a schematic diagram showing a second embodiment of the present invention.

FIG. 7 is a circuit diagram of the detection device shown in FIG.

FIG. 8 is a control circuit diagram of an ignition interlock.

FIG. 9 is a control circuit diagram of a shift lever interlock.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Detected gas suction part 12 Suction pipe 12a Opening 20 Sensor attachment part 22 Alcohol sensor 24 Humidity sensor 26 Sulfide sensor 30 Alcohol concentration judging device 40 Exhalation judging device 50 Display device 60 Suction pipe 60a Opening 62 Three-way valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-48-94128 (JP, A) JP-A-50-73340 (JP, A) JP-A-50-14034 (JP, A) JP-A 47-94 40994 (JP, A) JP-A-50-12725 (JP, A) JP-A-49-42186 (JP, A) JP-A-59-220421 (JP, A) JP-A-63-53120 (JP, A) JP-B-51-21698 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 10/00 A61B 5/08 B60K 28/00 B60Q 9/00

Claims (3)

(57) [Claims] 1. An inhalation unit having one opening (a first opening) facing a space to be measured, and a suction unit provided on a side of the other opening communicating with the opening, A sulfide sensor provided in the unit for determining whether or not human breath is contained in the inhaled gas to be detected; and an amount of exhaled gas provided in the inhaler and contained in the gas to be detected. A humidity sensor for calculating the following formula: an alcohol sensor provided in the suction unit, for detecting alcohol contained in the gas to be detected, and a detection signal of the sulfide sensor and a detection signal of the humidity sensor. A breath presence / absence determiner that determines the presence or absence of breath from the ratio, and an alcohol concentration determiner that determines the alcohol concentration from a ratio between the detection signal of the alcohol sensor and the detection signal of the humidity sensor, An alcohol detecting device for detecting an alcohol concentration in a gas to be detected passing through the inside. 2. The gas sensor according to claim 1, wherein a film for delaying gas diffusion is provided around the alcohol sensor, the sulfide sensor, and the humidity sensor so that gas response time constants are equal. Alcohol detection device. 3. The three-way valve according to claim 1, wherein the three-way valve is provided between the alcohol sensor, the sulfide sensor, and the humidity sensor and the first opening, and one end of a pipe is the three-way valve. And a second inhalation unit having a second opening, the other end of which is connected to the driver's seat in the passenger compartment and located at a position where it is difficult for the driver's expiration to be inhaled. Characteristic alcohol detection device.